Piston-rod packing.



PATENTED SEPT. ll, 1906.

A. L. SHAFP'ER. PISTON ROD PACKING.

APPLICATION FILED SEPT.12,1905.

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Specification of Letters Patent.

Patented Sept. 11, 1906.

Application filed September l2, 1905. Serial No. 278.088.

vuseful improvements in piston-rod packings,

and has for its object to provide a packing embodying a novel construction and arrangement of packing elements whereby increased durability and efliciency are insured.

The packing is especially adapted for use upon ammonia-compressors, as its lasting qualities prevent leakage and loss of ammonia to a material extent; but it is also adapted to be used with equal efficiency as a steam-l packing.

With this and other objects in view the invention consists of the novel construction and combination of parts hereinafter fully described and claimed, reference being had to the accompanying drawings, in which- Figure 1 is a longitudinal section through a vstuffing-box embodying my invention. F ig. 2 is an inner side view of one of the inner terminal fiber packing-rings. Fig. 3 is an edge view of the same, and Fig. 4 is a side view of one of the central or intermediate packing-rings.

Referring now more particularly t0 the drawings, the numeral 1 designates the piston-rod; 2, the stuffing-box, and 3' the gland of the stuffing-box, which is adjustably secured thereto by bolts 4.

Disposed within the box 2 are packing devices A and B. These are alike in construction, and therefore a description of one will suffice for both. Each packing device comprises a casing 5 of a size to fit snugly within the box and closed at its ends by heads 6 and 7, which have a screw-threaded engagement therewith. ln the casing 5 is a set of packing-rings consisting of a central ring 8, composed of a series of segmental sections, as shown in Fig. 4, and formed with a peripheral groove to receive a surrounding spring 9, whereby said ring is permitted to expand and contract about the piston-rod 1. On opposite sides of said central ring are arranged intermediate packing-rings 10, each of which is constructed of segments like the ring 8 to permit expansion and contraction and peripherally grooved to receive a spring 12, adapted to permit it to expand and contract about the piston-rod. Beyond each intermediate ring 10 a pair of terminal packing-rings surround the shaft, the inner terminal ring 13 being formed with an outer beveled face 14, while the outer terminal ring 15 is provided with an inner beveled face 16 to fit against said beveled outer face of the ring 13, whereby the rings fit one within the other, the expansion of the inner terminal ring being limited by the outer terminal ring. The inner terminal ring 13 is provided with a single slot or gap 13', or, in other words, is in the form of a split ring, while the outer terminal ring is unsplit or solid. The beveled surfaces of these rings permit the outer terminal ring to ride upon the inner terminal ring to contract and expand the latter when the rings are moved toward and from each other to obtain a uniform expansion and contraction, and thereby provide for the elimination of all crevices through which the steam or other medium contained in the cylinder to which the stuffing-box is attached may escape.

The central packing-ring S and intermediate packing-rings 10 are formed with fiat inner and outer faces, while the inner faces of the inner terminal disks 13 and the outer faces of the outer terminal disks 15 are also fiat, the meeting faces of the disks being arranged to contact. It will be observed that by providing the terminal disks with beveled faces said disks are given a substantially triangular formation and having their beveled faces so engaged and related as to provide for equal wear and an effective adjustment to compensate for wear. The central disk 8 and inner terminal disks 13 are preferably lmade of some suitable fibrous composition, such as rubber fiber, while the intermediate disks 10 and outer terminal disks 15 are made of some suitable alloy, such as Babbitt metal, thus providing a construction in which rings of fiber and Babbitt metal are alternately arranged, the fibrous disk having the requisite hardness to secure durability7 while-the metallic disks impart sufhcient ductility to maintain the surfaces in shape and to reduce friction to a material extent. fibrous disks are preferably formed with pits, grooves', or recesses 17 for the reception of oil or some other suitable lubricant which will allow the metal and fibrous rings to have freedom of action without danger of cohesion.

The fiat or abutting faces of the IOS The arrangement of the packing shown in Fig. 1, wherein two sets of packing devices A and B are disposed in tandem relation, is

. that employed when the stufling-box is used upon ammonia compressors and other devices wherein the expansive medium is under high pressure or is liable to escape on account of .its high volatility. In this arrangement packing-rings or gaskets 19 and 20 are disposed between the inner end ofthe stuffing-b ox and the adjacent head 7 of the casing A and between the gland 3 and the adjacent head 6 of the casing of the packing B, while a short gasket or packing-ring 21 is disposed between the two sets of packing devices. For'use as a steam-packing a single set of packing devices is sufficient, and it will be understood that when but a single set is disposed in the stufling-box a gasket will be arranged at each end of the casing 6 and between the respective heads thereof and the inner wall of the box and inner face ofthe gland 3.

Practical demonstration has shown that a packing constructed in accordance with my invention is not only comparatively inexpensive, but is highly efficient in operation and extremely durable, the form, construction, and material used in the production of the packing-rings serving to reduce wear, to maint ain a tight joint ab out the pist on-rod and permit free and easy independent movement of the rings with a minimum of resistance and without liability of cohesion. The arrangement of the packing-rings is, further, such as to form a joint which reduces to a minimum the loss of steam, ammonia, or other vfluid by leakage from the cylinder through the stuffing-box.

y I-Iaving thus described the invention, what is claimed as new isl 1. In a packing, a casing, a central packing-ring,interniediate packing-rings arranged on opposite sides of the central ring, terminal packing-rings arranged in pairs and abutting against the intermediate packing-rings, each pair comprising an inner ring having an outer beveled face and an outer ring receiving the same and formed with an inner beveled face,

said central and inner terminal rings being composed of fiber and the coperating rings of a metal alloy, and means for placing the rings under compression.

2. In a packing, a casing, a central packing-ring,intermediate packing-rings arranged on opposite sides of the central ring, terminal packing-rings arranged in pairs and-abutting against the intermediate packing-rings, each pair comprising an inner ring having an outer beveled face, and an outer ring receiving the same and formed with an inner beveled face,

, said central and inner terminal rings being composed of fiber and the coperating rings of a metal alloy, heads closing the ends of the casing and forming an abutment for one end of they packing, a follower bearing against the other end of the packing, and a coiled spring 'disposed between said follower and the other head.

3. In a packing, juxtaposed rings, one formed of a hard fiber and the other of a metal alloy, said rings having contacting faces, the face of one of the rings being pitted to form pockets for receiving and retaining a lubricant between the meeting faces of the rings to prevent cohesion thereof.

4. In a packing, a stuffing-box, and packing devices arranged in tandem therein, each packing device comprising a set of springpressed packing-rings, and an inclosing casing for each set of rings, each set being independently conned within its own casing.

5. In a packing, a stufHng-box, and packing devices arranged in tandem therein, each packing device comprising a set of springpressed packing-rings, an inclosing casing for each set of rings, each set being independently confined within its own casing, a gland acting on the outer end of the outercasing, and packing between the juxtaposed ends of the casing, substantially as described.

6. In a packing, the combination of a stuffing-box, a gland adjustably connected therewith, sets of packing devices arranged in tandem relation in said box, each being complete in itself and comprising a casing, heads closing the ends of the casing, packing-rings arranged within the casing and abutting against one of the heads, a follower for forcing the rings against said head, a coiled spring between said follower and the other head, and packing-disks between the juxtaposed heads of the packing devices and the opposite heads gf said devices and the ends of the stuffing- In testimony whereof I affix my signature in presence of two witnesses.

ADAM L. SHAFFER.

Witnesses:

CHAs. `D. BIRKETT, MADs A. HANSEN.

TOO

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